will not work (or there's at least a big possibility it won't) in IE (version 6 sure and I suspect lower versions as well) if you have session.auto_start on. Apparently, setting a cookie before feeding the fdf to the browser somehow messes it up. It works fine in Netscape though. I spent days on Google before I found a post somewhere about someone else having the same problem.

The solution? Well, I created a separate directory in the web tree and turned session.auto_start off just for that directory like this:

Header("Content-type: application/vnd.fdf"); simply does not work in IE. The easiest method to automatically load the fdf file is to open the 'pdf' file via php. With use of Acrobat document -> page action -> page open -> add -> javascriptand paste the following into the pdf file: